An organic light emitting diode (OLED) is concerned by people more and more. An OLED screen usually utilizes an amorphous silicon (a-Si) TFT for driving, however, an electron mobility of an a-Si TFT switch device is too low to satisfy a current driving scheme of the OLED screen. Accordingly, it is particularly important to change the a-Si into poly-silicon for lifting the electron mobility so as to improve electrical characteristics of the TFT switch device.
The current technique has shortcomings that the TFT is directly formed on a transparent substrate, therefore it is necessary to grow a multi-laminated structure thereon, in addition, it is also necessary to manufacture electrical connection structure between the TFT and external components, so that the working process is complicated, and the cost is higher.